The central concern of this research project is to assess the effects of a nutritionally sound, but potentially stressful low fat isocaloric diet on the marital system of the insulin dependent adult diabetic, and to identify marital patterns related to greater adjustment to dietary stress. The low fat diet, recommended recently by the American Diabetes Association's Committee on Food and Nutrition is a potential stressor both for the diabetic and the diabetic's family. The traditional diet already has severely controlled the consumption of concentrated sugars or carbohydrates. Introduction of the low fat diet calls for the reduction or elimination of fatty meats, dairy products and oils. A marital relationship with well developed and effective coping mechanisms may assist the diabetic in making these dietary changes. However, the diabetic's marital system has been stressed repeatedly by the diagnosis and all this implies, potentially reducing the ability of the marital dyad to withstand further stress. In addition, stress can adversely affect diabetes. Employing both an own control (with placebo diet change) and a control group design, three areas of response will be considered following introduction to and adherence to a low fat diet: (1) marital distress, which should initially increase, then decrease with adaptation to the new diet; (2) in spite of adverse effects of stress on diabetes, diabetic control should be maintained while blood lipids are reduced; (3) initially more adjusted marital dyads should show less marital distress to the introduction of the low fat diet and should demonstrate quicker recovery to the stress than initially less adjusted marital dyads. Marital distress will be indicated by greater displeases, desire for greater spousal change, less marital satisfaction and more need for prompting to adhere to the diet. Diabetic control will be assessed by serial determination of the concentrations of fasting glucose and the percentage of glycosylated hemoglobin. Blood lipids will be measured by fasting serum triglycerides and serum cholesterol.